Sparking plug for internal-combustion engines.



M. WILD. SPARKING PLUG FOR INTERNAL COMBUSTION ENGINES. APPLIOATION FILED NOV. 6, 1908.

1,004,325, I Patented Sept. 26, 1911.

' INVENTQR MAX WILD,

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WILD, OF STUTTGAR'I, GERMANY.

SPARKING PLUG FOR INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent.

Application filed November 6, 1908.

Patented Sept. 26, 1911.

Serial No. 461,279.

To all whom it mag concern:

Be it known that I, MAX WILD, a citizen of the German Empire, residing at Stuttgart, in the Kingdom of Wurttemberg, Empire of Germany, have invented certaln new and useful Improvements in Sparking Plugs for Internal-Combustion Engines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to electromagnetic make and break sparking plugs such as are employed in internal combustion engines The improved plug is of the kind in which the armature carrying the movable electrode turns on its longitudinal axis and, together with the magnet core which actuates 1t, is arranged in a coil, the armature lying in a recess of the magnet core. Now the present invention is distinguished from similar known sparking plugs of this kind by its simple construction and the ease of operation of the magnet core. To attain these results the armature is provided with studs by means of which the armature rests on the magnet core and the sharp edges of which form the pivot for the armature. However this arrangement can be reversed. Around the magnet core and the armature a spring is placed, which holds the armature and returns it to the position of reposez'. 6., the position in which the armature is most remote from the magnet core and the sparking contacts touch. Now this spring may be of such a form that it engages around the magnet core by means of a single coil only, but is provided with a longitudinal arm, having a sharp edge or point which bears against the armature. By this arrangement extremely free movement of the armature is obtained without however any danger of jamming, and a certain operation even at high speeds is insured.

The invention will now be more particularly described in connection with the form I of construction shown in an example in the accompanying drawings, in which Figure 1 is a longitudinal sectional view of the sparking plug, artly in elevation,

with the armature and spindle removed.

I Fig. 2 is a similar View taken at right angles to Fig, 1, the armature and spindle be ing shown in assembled position. Fig. 3 is a cross section of same; Fig. 4 is a perspective view of the armature; Fig. 5, another form of construction of the plug shown in axial longitudinal section; while Fig. 6 is a perspective view of the spring employed therewith.

In a sparking plug made in accordance with this invention, the magnet core a is arranged in the ordinary way in a coil 1) which may be inclosed by a casing a. This casing c is again in turn mounted in a holder d which is screwed in the cylinder head 6. Current is conveyed into the coil by way of the contact screw f which is suitably connected to the upper end of the core and is insulated from the casing 0 as shown. The other end of the coil is electrically connected to the armature in any suitable manner as, for instance, by a small binding screw or by soldering. The lower end of the armature is connected to the armature spindle g which passes through an insulated portion 72. and passes then to the movable electrode 6 which bears against the fixed electrode is connected with the body of the engine.

Thus the current may pass from its source to the screw f and thence through the coil 5, the armature, the armature spindle and the fixed electrode. The insulation it together with air gaps passing around the holder 03, the core a and the armature Z insulate the same from the casing c and the cylinder head 6. The magnet core a is laterally recessed for receiving the armature l to which the spindle g is attached, and which by means of studs or points on formed on the magnet core a is pivotally mounted on said magnet core. These studs m are preferably prismatic in form and lie in a line with the spindle g, and are loosely received by larger but similarly shaped recesses in the inner face of the armature. In order to hold the armature Z in place, a spring 12. is placed around the core a and armature Z, and received in recesses in the outer surfaces of said core and armature. Said spring always tends to return the armature to its normal position as far as possible from the core, in which position the movable electrode 11 and the fixed electrode is are in contact.

The mode of operation of the sparking plug is as follows :On the closing of the circuit the magnet core a is excited and then attracts the armature Z against the action of its spring a, whereby the movable electrode 2' is drawn away from the fixed electrode is and an igniting spark is pro duced. The armature Z turns on the pivot formed by the sharp edges of the studs m, whereby it has an extremely free movement and secure guidance. The armature spindle g has some play, as "it does not tightly fit in the insulation h, but .the armature Z is merely carried by the spring a.

In the form of construction shown in A Figs. "5 and 6 the spring at engages the arna1ly of said core; a semi-cylindrical armature loosely fitting in said semi-cylindrical recess, and having an inner flat surface, and provided with an outwardly openmature core a by means of a single coil which merges into a longitudinal arm 0 by means of which it acts on the armature Z. For this object the arm 0 is provided with a sharp edge p which bears against the armature Z, in such a manner that it stands under a spring action. The other end of the coil may also end in a projecting part. There is thus here also great freedom of movement of the armature Z insured. The armature and the core are each provided with a longitudinal outwardly opening recess for the reception of said ends respectively of the spring 11/.

I declare that what I claim is 1. In a make and break spark plug, the combination of an electromagnetic coil; a core in said coil and provided with a substantially semi-cylindrical recess having afiat face; a series of studs projecting from said flat face and arranged longitudinally and eccentrically of the core; a semi-cylindrical armature loosely fitting in said semicylindrical recess and having an inner face provided with a series of recesses loosely receiving said studs whereby said armature may be rocked toward or from the core; a movable contact carried by the armature and electrically connected therewith; a stationary contact adapted to be contacted by the movable contact when the armature is in outward position; and means for yieldably holding the armature in outward position.

2. In a make and break spark plug for explosive engines, the combination of an electromagnetic coil; a core in said coil and recessed to substantially half its thickness forming a substantially semi-cylindrical recess having a longitudinal fiat face, and provided with an outwardly opening recess in its outer face; a series of studs projecting from said face and arranged longitudiing recess in its outer face; a contact spindle extending longitudinally from said armature and electrically connected to said coil, the inner flat surface of said armature being provided with a series of inner recesses in alinement with said spindle and loosely receiving said studs, whereby a pivotal connection is formed between the core and armature; a stationary contact; a movable contact on said spindle and adapted to move into or out of contact with said stationary contact as the spindle and armature pivotally move; and a spring consisting of a singleucoil and provided with elongated flat portions engaging in said outwardly opening recesses in the outer surface of the core and armature respectively and adapted normally to hold said core and armature at their position most distant from each other and to hold said contacts normally in contact.

In testimony whereof I affix my signature, in presence of the witnesses.

MAX IVILD.

Copies of this patent may be obtained for five cents each, by addressing the "Commissioner of Patents. Washington, D. C. 

